Jaguar XJ6 (X300) Trunk Won't Open, Boot Release
On the X300 the boot opens electrically or with the key, and the battery lives inside it, so a flat battery is the commonest way to be shut out. Feed power to the jump post under the bonnet, or free the seized key lock with the black master key. If the car has power and a button still does nothing, I'd look at the lid button and the wiring at the right-hand boot hinge.
How bad is it · Safe to drive
Safe to drive, but never crank the engine from the post under the bonnet
A shut boot doesn't stop the car, though it hides the battery. The cable to the under-bonnet post isn't built for starter current and can catch fire: use it only to open the boot, then jump at the battery itself.
Which one applies to yours depends on your symptoms, your model year and what has already been done to it.
Likely causes, most common first
Read the check cost before the odds: a free check that rules a cause out beats a likely guess that costs money.
Flat battery: the release is electric and the battery is in the boot
The dash button, the fob and the button on the lid all need power, and on the X300 the battery sits behind the lid they open. With the battery flat, only the key lock or outside power gets you in.
Nothing at all from any button or the fob, typically after the car has stood for weeks or after the battery was disconnected with the boot (trunk) shut.
Under the bonnet there is a positive jump post under a rubber cap by the engine-bay fuse box, one on each side; the thick cable from it runs back along the inner wing. Clip the positive lead there and the negative to bare engine or body metal, then press the dash button or the fob.
Use a healthy car battery or a strong booster: a small jump pack or a charger can light the lamps and still not have enough to pull the boot solenoid. Once the lid is up, move the leads to the battery itself. If the battery was out of the car, make sure its positive lead isn't lying on metal before you apply power. Keep the donor car's engine off while its battery boosts the Jaguar, never use more than 12 V, and put the negative lead on bodywork rather than the flat battery.
The key lock in the boot has seized
The key lock is purely mechanical, so it's the way in when there's no power. It's hardly ever used, and after years the barrel seizes.
The key goes in but turns only part of the way or not at all; it should turn a quarter turn clockwise.
Use the black master key, not the green one. Spray penetrating oil into the keyway and work the key gently back and forth, many times over; don't force it. On a Vanden Plas a keyhole may sit in the badge on the left of the lid, easy to miss.
Freed this way, the key opens the lid. Afterwards replace the spray with a proper lock lubricant or powdered graphite, and use the key now and then; a barrel that never frees needs replacing. Test the boot key before you ever disconnect the battery.
The button on the boot lid itself
The release button on the lid is a small switch that gets dirty or simply dies. The dash button and the fob still open the boot; only the lid button fails.
The lid button is dead, or works for a while and then stops for a few days; the dash button opens the trunk normally.
Take the button out and meter it while pressing. A button that shorts inside can also set the alarm off.
Cleaning and lubricating the switch often brings it back; a pin hole in the back and a shot of contact cleaner works too. Otherwise a new switch, or a microswitch of the same size and mounting, is a five-minute fit.
The car thinks the boot is open: latch microswitch or a loose lid
A microswitch in the latch tells the security module whether the lid is shut. When it misreads, the boot release, the locking and the alarm all misbehave together.
The boot-open warning stays lit with the lid shut, the buttons won't open it and locking gives a warning tone; at worst the car won't crank, and a failed switch can flatten the battery.
Push down hard on the shut lid and watch whether the warning clears. Look at the latch alignment, then at the microswitch and its wire.
A loose lid needs realigning, and the switch renewing if it has failed, part LNA6242AC. Unplugging a failed switch brings the locking back meanwhile, at the cost of the boot lamp and the warning.
A bulkhead plug left loose after fuel tank work
A large multi-pin plug on the right of the rear bulkhead, above the fuel tank, carries several circuits at once. Disturbed during a fuel pump job, it takes the boot release down with the gauges, the radio and the central locking.
The boot release died together with the gauges, radio and locking, right after work on the fuel tank or pump.
Open the boot with the key and find the plug with the plastic latch on the right-hand side of the bulkhead above the tank.
Reseating it properly brings everything back at once.
Radio and boot release dead together: the shared fuse in the boot
One 15 A fuse in the boot fuse box feeds the central locking and security system together with the radio. A short in radio wiring takes the boot release down with it.
The boot button stopped at the same moment as the radio, typically right after a radio was changed or wired in through an adapter lead.
Open the lid with the key and look at F8, 15 A, in the boot fuse box. The 25 A fuse beside it feeds only the radio amplifier, so a good one there proves nothing.
Fit a new fuse, then find the short in the radio wiring before it blows again; an aftermarket radio is better on its own properly fused feed.
Broken wires in the loom at the right-hand boot hinge
The loom into the lid bends at the right-hand hinge every time the boot opens. The copper work-hardens and snaps inside insulation that still looks intact.
The lid button is dead, often with the number plate lamps or the boot lamp out as well; sometimes the trunk-open warning and the alarm play up too.
Take off the hinge cover, cut the cable tie nearest the bend, open the loom tape and test each wire for continuity while flexing it. Radial cracks in the insulation nearly always mark a break; a thin red/white wire is a frequent one. A quick test first: press the fob twice. The second press should open the lid; doors that answer while the boot stays shut point at these wires.
Worth trying: join each broken wire with solder or a straight crimp and leave off the tie that bent them. Look here before buying an actuator, because a new actuator won't cure a broken wire.
The lock motor runs but its rods have come off
Two thin rods run to the latch, one from the actuator and one from the key lock, held by plastic clips. The clips age and the rods drop off, more so on lids that get slammed.
Press the button and you hear the motor in the lid run, but the lid stays shut; the key still opens it.
Open the boot with the key, unclip the lid trim and look at both rods at each end; the actuator sits behind the keyhole. A little graphite powder on the key frees the key lock while you're there.
Worth trying: refit the rods, set the length at the actuator end so it has enough travel, and back up the clips with a cable tie.
Valet mode, or the key left in the ignition
Valet mode locks out the boot buttons, and on some cars the outside button is disabled while the key is in the ignition. This varies with market and dealer setting.
The doors work normally but the boot buttons do nothing, or one works and the others don't; the key still opens the lid.
Take the key out of the ignition and try again. Check the valet switch in the centre console storage under the armrest.
Worth trying: cancel valet mode; on some cars a press of the fob clears it.
The wrong key: the valet key never opens the boot
The X300 came with a master key and a valet key. The valet key starts the car and works the doors, but not the boot or the glovebox.
The key enters the boot lock but won't turn, though it works the ignition.
The master key has an extra small step near the tip; the valet key lacks it. The valet key is usually green, but not always.
Worth trying: the master key opens the boot by hand with no power at all.
The order to check them in
The point of the order is money: each step either rules a cause out or makes the next one worth doing. Green is free, amber costs a little, red is the one to arrive at last.
Dead battery? Power the jump post under the bonnet, then press the release
A healthy car battery, not a small pack. Never crank the engine from that post.
freeTry the black master key in the boot lock
Penetrating oil and patience if it won't turn.
freeKey out of the ignition, valet mode off, then each button in turn
Dash button, fob and lid button: which ones fail tells you where to look.
freeNo power and no key: reach the latch through the holes behind the number plate
Peel the black tape off the lower right holes and go in with a long thin screwdriver or a bent hanger, up and to the left, with a torch. Don't stab about: a spring or the boot lamp switch can be knocked loose, and the lamp switch then needs pushing back.
freeLid button dead but the dash button works: the switch, then the hinge loom
Clean or replace the switch; flex-test the wires at the right-hand hinge.
cheapMotor runs, lid stays shut: the rods behind the lid trim
Refit both rods and secure the clips.
freeTrunk-open warning with the lid shut: alignment and the latch microswitch
Push the lid down and watch the warning.
cheapLast resort: drill behind the number plate
A hole of about 20 mm (3/4 inch) in the centre of the lower plate recess, hidden by the plate, reaches the latch lever with a screwdriver. It is permanent damage to the body, so only when everything above has failed; paint the bare edge and tape the hole.
paint for the bare metalThe fuses named above — where they sit
The highlighted position is the one the procedure talks about. Pulling a fuse is a stop-gap, never a repair: check what the circuit feeds before you pull it.
Circuit descriptions from the Jaguar fuse tables, 1995 edition. Drawing by jagaux.com from the factory electrical guide. Fuse layouts change between model years — read the legend on the lid of your own box before pulling anything.
What it usually isn't
Don't spend money here first:
If none of this finds it:
On jagaux.com
- Jaguar XJ6 (X300) Battery Drain, Flat BatteryIf the battery keeps going flat and shutting you out of the boot.
- Jaguar XJ6 (X300) Key Fob Not Working, Fob ProgrammingIf the doors won't answer the remote either.
- Jaguar XJ6 (X300) Power Antenna Stuck or DroppingIf the aerial runs on and you're tempted to pull its fuse: shut the boot first.
- XJ6 (X300) fuse boxes and relaysThe boot fuse box sits in front of the battery; 1996 and 1997 from the same page.
- Jaguar radio code generatorFree. For when the radio asks for its code after the battery has been off.
- Jaguar XJ6 (X300) Alarm Keeps Going OffIf the alarm goes off on its own as well: same boot switch and hinge loom.
- Jaguar XJ6 (X300) Radio Not Working or Buttons DeadIf the radio died at the same moment as the boot release.
- Jaguar VIN decoderConfirm your exact model year, engine and factory options before ordering parts — free.
Ratings, fuse numbers and torque figures vary by model year and market. Read the legend on your own car before pulling anything, and use the figures in the manual for your car, not the ones in a video.
Check your VIN: exactly which car you have and which bulletins apply to it.